Increasing urban growth and global construction surges have underscored the importance of efficiency in the built environment. In the United States, buildings account for over a third of total energy use, two-thirds of electricity consumption, one-twelfth of the country's water consumption, and two-fifths of carbon dioxide emissions.
Agriculture has an equally significant impact on our world. Modern agriculture feeds billions of mouths every day, but is the world's largest consumer of land and water, the source of most water pollution, and the source of an estimated 15% of the world's greenhouse gas emissions. Three major trends will strain the global food system over the next half-century, and place significant additional pressure on the environment.
First, according to official UN estimates, global population is expected to exceed nine billion by 2050. Second, more than two-thirds of these people are expected to be urban dwellers. Urbanization requires that food, once grown and harvested, must travel hundreds or thousands of kilometers to reach consumers. Fresh produce travels an average of 2500 km to reach U.S. cities, adding to traffic congestion, air pollution, and carbon emissions. Third, global warming is predicted to lead to widespread shortages of food, water, and arable land by 2050 within a broad belt extending north and south of the equator and encompassing some of the world's most populous regions.
Growing food crops on or in buildings can help reduce our environmental footprint, cut transportation costs, enhance food security, save energy within the building envelope, and enrich the physical and psychological comfort of building occupants.
Hydroponics, the culture of plants in water, is a technically sophisticated commercial practice in most regions of the world. As publicly demonstrated by New York Sun Works at the Science Barge greenhouse in Manhattan, recirculating hydroponics can produce premium-quality vegetables and fruits using up to 20 times less space and 10 times less water than conventional agriculture, while eliminating chemical pesticides, fertilizer runoff, and carbon emissions from farm machinery and long distance transport.